Neutrino Factory and Muon Collider R&D - Advanced Accelerator

Neutrino Factory and Muon Collider R&D

Muon Production, Capture and Acceleration R&D directed at Physics with Intense Muon Beams

The Neutrino Factory and Muon Collider Collaboration

Alan Bross High Energy Physics Advisory Panel Meeting July 14, 2007 2

A Bit of History

Since 1995 the Neutrino Factory and Muon Collider Collaboration (a.k.a. Muon Collaboration) has pursued an active R&D program that has focused on muon production, capture and acceleration. Initially the physics emphasis was on muon colliders (both a Higgs Factory and an energy frontier machine). By 2000 the focus of the collaboration had shifted to studying the feasibility of a Neutrino Factory. Recently new ideas in muon ionization cooling have reinvigorated the collaboration's efforts on the investigation of energy frontier muon colliders. I will:

1. Review the physics motivation for our activities2. Describe the Collaboration's program3. Explore the synergy between Neutrino Factory and Muon

Collider facilities both from the point of view of the physics program and the accelerator complex


NFMCC Mission

To study and develop the theoretical tools, the software simulation tools, and to carry out R&D on the hardware that is unique to the design of Neutrino Factories and Muon Colliders

• Extensive experimental program to verify the theoretical and simulation predictions

NFMCC WEB site: http://www.cap.bnl.gov/mumu/


Current Organization

R&D Tasks

DOE/NSF

Laboratories/MCOGP. Bond, S. Holmes, J. Siegrist

MUTACR. Kephart

CollaborationSpokespersonsA. Bross, H. Kirk

ProjectManager

M. Zisman

Simul. µCOOL Target MICE

ExecutiveBoard

TechnicalBoard

Collaborating Institutions

Neutrino Factory and Muon Collider Collaboration (NFMCC)

Other


Collaborating Institutions

US International

National LabsArgonne

BNLFermilabLBNL

Oak RidgeThomas Jefferson

UniversitiesColumbiaCornellIIT

IndianaMichigan State

MississippiNorthern Illinois

PrincetonUC-BerkeleyUC-Davis

UC-Los AngelesUC-Riverside

University of Chicago

National LabsBudkerDESYINFN

JINR, DubnaKEKRAL

TRIUMF

UniversitiesKarlsruhe

Imperial CollegeLancaster

OsakaOxfordPohangTel Aviv

Corporate PartnersMuons Inc*

Tech-X Corporation

*SBIR Funding9 Phase I6 Phase IICurrently 8 FT Ph.D.


Core Program

Targetry R&D: Mercury Intense Target Experiment (MERIT)

Co-Spokesperson: Kirk McDonaldCo-Spokesperson & PM: Harold Kirk

Ionization Cooling R&D: MuCool and MICEMuCool Spokesperson: Alan BrossMICE Deputy Spokesperson: Mike ZismanUS MICE Leader: Dan Kaplan

Simulations & TheoryCoordinator: Rick Fernow

Muon Collider Task Force*

*@ Fermilab

Physics Motivation

Is Muon Production, Capture and Acceleration R&D worth the investment?


Evolution of a Physics Program

1. Intense Low-energy muon physics

µ e conversion experiment2. Neutrino Factory

High Energy 10-20 GeVPossible Low Energy 4 GeVoption

3. Energy Frontier Muon Collider

1.5 - 4 TeV+

PRSTAB 2002


Footprint and the Energy Frontier

ILC0.5 → 1.0 TeV (?)

• The VLHC is the largest machine to be seriously considered to date

Stage 1 – 40 TeV> 2 TeV

Stage 2 – 200 TeV> 10 TeV

73km

ILC

CLICCLIC

3 TeVMuon Facilities

are different

Compact Lepton MachineCLEM (2 TeV) 10


Low-Energy Muon Physicsµ to e conversion - Mu2e

• Sensitive tests of Lepton Flavor Violation (LFV)

In SM occurs via ν mixingRate well below what is experimentally accessible

Places stringent constraints on physics beyond SM

Supersymmetry– Predictions at 10-15

• Requirement – Intense low energy µ beam

Cooling improves stopping efficiency in target of experiment

Might be an appropriate option for a Mu2e expert.

– Time Scale is issueTest bed for Muon Ionization Cooling for NF and MC with intense µbeam

µ e

NN


Neutrino Factories

Preliminary Design From the International Scoping Study

• Why a Neutrino Factory?Strong case for precision neutrino program

Very Rich Experimental Program

• Want Very Intense νbeam with well-understood systematics


Low-Energy NFNeutrino Factory Lite

25-50 GeV 4 GeV

40% CostReduction

ISS Preliminary Design


3 ν Mixing Model

Is a Neutrino Factory needed in order to fill in the blanks?


Neutrino Factory- ISS

(3σ, ∆m312=0.0022 eV2)

Best possible reach in θ13 for all performance indicators → Neutrino factory


Theoretical Indications That θ13 may be small

Projections of the allowed regions from the global oscillation data at 90%, 95%, 99%, and 3σ C.L.

Maltoni et. al. hep-ph/0405172 June 2006


sin2θ13 Model Predictions

Histogram of the number of models for each sin2θ13 bin.

Albright and Chen, hep-ph/0608137 August 2006


Neutrino Factory To Build or Not to Build

We Don’t Know –But

There is a Natural Decision Point≈ 2012

After NOvA and T2KIf θ13 not seen

orseen at 3σ

Consider Major Upgrades orNew Facility

In order to make an informeddecision about a New Facility and if the NF plays a role –

Will need a RDR ready at this time (IDS)

This defines the R&D Program

Double Chooz/Daya Bay

FNAL → DUSEL


Muon Collider - Motivation

Reach Multi-TeV Lepton-Lepton Collisions at High Luminosity

Muon Colliders may have special role for precision measurements.

Small ∆E beam spread –Precise energy scans

Small Footprint -Could Fit on Existing Laboratory Site


Muon Collider at the Energy Frontier

• Comparisons with Energy Frontier e+e- Collider

For many processes - Similar cross sectionsAdvantage in s-channel scalar production

Cross section enhancement of (mµ/me)2

– ≈ 40,000Beam polarization also possible

Polarization likely easier in e+e-

machineMore precise energy scan capability

Beam energy spread and Beamstrahlhung limits precision of energy frontier (3TeV) e+e-

machinesMuon decay backgrounds in MC do have detector implications, however

3 TeV COM Visible Ecm

CLIC Simulation


MC Physics - Resolving degenerate Higgs

For larger valuesdiscovery at LHC or gau

of tanβ there is a range of heavy Higgs boson masses (H0, A0) for which e+e- linear collider may not be possible due to suppression of coupling to

ge bosons

Precision Energy ScanCapability

of Muon Collider


Davide Costanzohep-ex/0105033v2

Key Ingredients of the Facilities


Needs Common to NF and MC Facility

• Proton Driverprimary beam on production target

• Target, Capture, and Decaycreate π’s; decay into µ’s

• Phase Rotationreduce ∆E of bunch

• Coolingreduce emittance of the muons

Cost-effective for NFEssential for MC

• AccelerationAccelerate the Muons

• Storage Ringstore for ~1000 turns


But there are Key Differences

Neutrino Factory Muon Collider

• CoolingReduce transverse emittance

ε┴ ~ 7 mm• Acceleration

Accelerate to 20-40 GeV

May be as low as 5-7 GeV

• Storage RingNo intersecting beams

• Bunch Merging

• CoolingReduce 6D emittance

ε┴ ~ 3-25 µmεL ~ 70 mm

• AccelerationAccelerate to 1-2 TeV

• Storage RingIntersecting beams


Key R&D Issues

High Power Targetry – NF & MC (MERIT Experiment)Initial Cooling – NF & MC (MICE (4D Cooling))200 MHz RF - NF & MC (MuCool and Muon’s Inc)

Investigate operation of vacuum RF cavities in presence of high magnetic fieldsInvestigate Gas-Filled RF cavities

Operation in B field and Beam-Induced EffectsWhile obtaining high accelerating gradients (~16MV/m)

Intense 6D Cooling – MCRFOFO “Guggenheim”Helical Channel Cooling (MANX Proposal)Parametric Resonance Ionization Cooling

Bunch RecombinationAcceleration– A cost driver for both NF & MC, but in very different ways

FFAG’s – ( Electron Model Muon Accelerator - EMMA Demonstration)Multi-turn RLA’s

Storage Ring(s) – NF & MCTheoretical Studies NF & MC

Analytic CalculationsLattice DesignsNumeric Simulations

Note: Almost all R&D Issuesfor a NF are currently under

theoretical and experimental study


Muon Ionization Cooling

Absorber Accelerator Momentum loss is opposite to motion, p, p x, p y, ∆ E decrease

Momentum gain is purely longitudinal

Large emittance

Small emittance

Longitudinal -Emittance ExchangeTransverse


NF, Muon Collider - Synergy

Neutrino Factory –ISS Preliminary Muon Collider Schematic


Additional Technologies Needed for a Muon Collider

• Although a great deal of R&D has been done (or is ongoing) for a Neutrino Factory and is applicable to a MC, the Technological requirements for a Muon Collider are Much More Aggressive

Bunch Merging is requiredMUCH more Cooling is required ( MAKE OR BREAK FOR MC ! )

1000X in each transverse dimension, ≈ 10X in longitudinal

Acceleration to much higher energy (20-40 GeV vs. 1.5-3 TeV)Storage rings

Colliding beamsEnergy loss in magnets from muon decay (electrons) is an issue

Palmer et al:RFOFO RingGuggenheim50-60T Solenoid Channel

Muons Inc.High pressure gas-filled cavitiesHelical Cooling ChannelReverse Emittance ExchangeParametric Resonance Induced Cooling


6 Dimensional Cooling

RFOFO Ring Guggenheim “Ring”


Helical Cooling Channel

• Magnetic field is solenoid B0+ dipole + quad + …• System is filled with H2 gas, includes rf cavities• Cools 6-D (large E means longer path length)

6D-MANX ExperimentTo Test


Extreme µ Cooling -PIC & REMEX

• Parametric-Resonance Ionization Cooling

Drive a ½-integer parametric resonanceHyperbolic Motion

xx’=constant• Reverse Emittance

ExchangeIncrease longitudinal ε in order to decrease transverse ε

Space-Charge Effects Could be Critical


Low-Emittance Muon Collider (LEMC) Concept

Parameter List:

Ecm = 1.5 TeVPeak L = 7X1034

#µ’s/bunch = 1011

Av Dipole B = 10Tδp/p = 1%β*(cm) = 0.5 (!)

Proton driver:E = 8 GeVPower ≈ 1 MW

ILC AcceleratingStructure Envisioned

Scientific Program

R&D InitiativesTargetry, Muon Cooling, Theory and Simulation

MERIT

Mercury Intense Target


MERIT –Mercury Intense Target

• Test of Hg-Jet target in magnetic field (15T)• Submitted to CERN April, 2004 (approved April 2005)• Located in TT2A tunnel to ISR, in nTOF beam line• Physics Data Run – Oct-Nov, 2007

Single pulse tests equivalent to 4 MW Power On Target40 Hz @ 24 GeV

Movies of viewport #2, SMD camera, 0.1 ms/frame

37

nozzle A before reaming

ORNL 2006 Nov 28 runs10 m/s

ORNL 2006 Nov 29 run, uprighted imageNozzle C 20 m/s

nozzle A after reaming


Magnet and Hg Jet system installedin TT2A tunnel at CERN

MuCool


Muon Cooling: MuCool Component R&D

MuCool201 MHz RF Testing

50 cm ∅ Be RF window

MuCoolLH2 Absorber

Body

• MuCoolComponent testing: RF, Absorbers, Solenoids

RF – High Gradient Operation in High B fieldUses Facility @Fermilab (MuCool Test Area –MTA)Supports Muon Ionization Cooling Experiment (MICE)

MuCool Test Area


Phase I of RF Cavity Closed Cell Magnetic Field Studies (805 MHz)

• Data seem to follow universal curve

Max stable gradient degrades quickly with B field

• Sparking limits max gradient• Copper surfaces the problem

Grad

ient

in

MV/

m

Peak Magnetic Field in T at the Window


Next 805 MHz study - Buttons

• Button testEvaluate various materials and coatingsQuick Change over

Tantalum Tungsten Molybdenum-zirconium alloyNiobiumNiobium-titanium alloyStainless steel


RF R&D – 201 MHz Cavity Design

• The 201 MHz Cavity is now operating tested to design gradient - 16MV/m at B=0 and at B= a few hundred Gauss

Did Not Condition!

Note: This cavity was assembled atTJNL using techniques/proceduresused for SCRF


Future Tests of 201 MHz Cavity Operation in Magnetic Field

• Need Coupling Coil (2.5T) MICE design

Shown in green schematicallyTHIS IS A CRUCIAL TEST FOR MICE AND FOR NF & MC in general

High Gradient RF operation in a magnetic field


High Pressure H2 Filled Cavity WorkMuon’s Inc

• High Pressure Test Cell• Study breakdown properties

of materials in H2 gas• Operation in B field

No degradation in M.S.O.G. up to ≈ 3.5T

No DifferenceB=0 & B=3T


Absorber R&D

• Two LH2 absorber designs are being studied Handle the power load differently

• Also considering LiH (solid) for NF Cooling

Forced-Convection-cooled. Has internal heatexchanger (LHe) and heater – KEK SystemTested @MTA to 25W → 100W

Forced-Flow with external cooling loopMuon Collider

MICE


Muon Ionization Cooling Experiment (MICE)

MICEMeasurement of Muon Cooling

Emittance Measurement @ 10-3

First Beam January 2008

Beam linecommissioning starts Jan 08

Winter 2008

Spring 2008

Neutrino Factory Decision Point≈ 2012


Muon Ionization Cooling ExperimentMICE

Beam Diffuser

FocusCoils

LiquidHydrogenAbsorbers

RFCavities

Tracking Spectrometers

MatchingCoils

Radiation shield

Magneticshield

CouplingCoils


US MICE

• Tracker ModuleSolenoidsFiber ribbonsVLPC System

VLPCs, Cryostats and cryo-support equipment, AFEIIt (front-end readout board), VME memory modules, power supplies, cables, etc

• Absorber Focus Coil ModuleLH2 and vacuum safety windows

Fabrication and QC• RF Module

Coupling Coils (with ICST of Harbin University, China)RF Cavities

• Particle IDCerenkov

Design and Simulation


Key Simulation Studies

• Muon Capture and Bunch RotationUses “standard” cooling componentsKeeps both µ+ and µ-

• Performance of Open Cell RF latticeMight mitigate problems with high-gradient RF in B field if not solved in RF R&D program

• Full optimization of acceleration scheme for NFPast year spent on International Scoping Study → International Design Study for a NF

Arrive at Reference Design Report• Full simulation and performance evaluation of PIC and REMEX• Complete baseline cooling scheme for a Muon Collider• Acceleration scheme for a Muon Collider• Design of low-beta collider ring


Acceleration

Dogbone RLA - footprint

-5000

-3000

-1000

1000

3000

5000

-15000 -10000 -5000 0 5000 10000 15000 20000 25000 30000 35000

z [cm]

x [cm]µ+

µ−

µ+

µ−


NFMCC 5 Year Budget Plan

Base Program funds: remain as in FY06: BNL ($0.9M); Fermilab ($0.6M); LBNL ($0.3M)

Including Base: About $3.6M per year plus supplemental ($400k in FY06)


Conclusions

• Neutrino FactoryCompelling case for a precision neutrino program exists

With present assumptions Neutrino Factory out-performs other options. However, more is needed before concluding this is the right path

– What the on-going Neutrino Physics program tells us (θ13)– Cost and schedule considerations

The collaboration is making excellent progress on R&D on the major sub-systems

Targetry – MERITMuon Cooling – MuCool and MICEAcceleration Design Studies

– FFAG• Also participating in the EMMA experiment in the UK

– RLAStrong Participation in the recently completed International Scoping Study

Move on to the International Design Study– Goal is to deliver a RDR by 2012


Conclusions II

• Muon ColliderNew concepts in muon cooling improve the prospects for a multi-TeV Muon Collider

Many new ideas emergingFront-end is the same or similar as that for a Neutrino Factory

Definite Synergies with NF R&DFirst end-to-end muon cooling scenario for a Muon Collider has been developed

• Much more to doDetailed simulation and analysis of cooling designs

Space charge and loading effects particularly important in final stages6D Cooling experiment(s)

– Converge on a preferred cooling schemeAccelerationCollider ring

• The NFMCC will work closely with the Fermilab MCTFMuon Collider Coordination Group

Kirk, Bross, Zisman, Shiltsev, Geer

Documents

Neutrino Factory and Muon Collider R&D - Advanced Accelerator